Developing an ion-exchange technique for the determination of metal bioavailability in fresh, brackish and marine waters

The Crémazy lab ( in the Department of Biological Sciences at the University of New Brunswick, Saint John (UNBSJ) is looking for a strong and motivated student with interests in environmental chemistry and biogeochemistry, to carry out a research project on the characterization of metal bioavailability in natural waters of varying salinity.

Project description: Metal pollution in estuarine and coastal waters is a growing world-wide problem, one with particular relevance in Canada. Total metal concentration ([M]) offers limited insights into metal ecological risk in natural waters. Indeed, metal bioavailability to aquatic organisms is better predicted by the concentration of free metal ions ([Mz+]), which varies with local water physico-chemistry (e.g. pH, dissolved organic matter concentration, salinity). The ionexchange technique (IET) is one of the rare techniques that can selectively measure Mz+ species in natural waters. In this technique, the water is equilibrated with a cation-exchange resin and the amount of metal that binds to the resin (measured by atomic spectroscopy) is proportional to [Mz+] in solution. To date, the IET has only been tested in freshwater and its applicability in estuarine and marine waters remains to be established. The goal of the proposed project is to develop an IET for the measurement of [Mz+] in the full salinity range encountered in natural waters.

We will focus on four metals that are historically important to the Canadian and the New Brunswick mineral sector: copper (Cu), lead (Pb), nickel (Ni) and zinc (Zn). The key milestones will be: i) to build an IET system in the lab; ii) to calibrate the technique for each metal at varying salinity; iii) to test its selectivity and optimize the protocols (e.g. equilibrium time); and iv) to test the IET with natural water samples collected from the field.

Requirements: Applicants should have a BSc degree by time of appointment, be passionate about environmental research, have a good work ethic and strong communication skills. Prior experience in analytical chemistry, environmental chemistry, and/or geochemistry is an advantage.
Start date: Preferably September 2019, but starting date is flexible.
Funding: A full competitive stipend will be offered.
Application: To apply for this position, please email the following to i) a CV; ii) a description of your background and interests; iii) your academic transcripts; iv) the contact information for at least two references. Preference will be given to applications received by May 15, 2019, but application review will continue until the position is filled.